It's a very slow process. Tried 3" discs on my drill. Result, more scratches because rpm was too low and it didn't take the original scratches out. Stepped it up with a variable speed buffer and a 6" disc using 320 grit wet sanding discs. That removed about 95% of the original scratches. Now I'm using an orbital sander with 600 grit wet sandpaper. 1200 and 2000 grit yet to go then the cerium oxide with the big buffer. It's a very slow process to say the least. Way more than I anticipated going into it. The Diamondite product seems like it would work the best but it's back ordered everywhere I've looked.